Power conversion device

Abstract

In a power conversion device, a plurality of channels of a first multiple access method are respectively allocated to a plurality of groups. A plurality of subchannels of a second multiple access method which are divisions of a corresponding channel of the first multiple access method are respectively allocated to a plurality of wireless nodes included in each of the plurality of groups. A first transmitter of each wireless node transmits individual information received from a connected submodule to a second receiver of a control protection device via an allocated channel and subchannel. A second transmitter of the control protection device simultaneously transmits a common control protection command to respective first receivers of the plurality of wireless nodes via a channel that is different from the plurality of channels of the first multiple access method.

The invention claimed is: 
     
         1 . A power conversion device comprising:
 an arm including a plurality of submodules, the plurality of submodules each being used as a unit converter, and being mutually cascade-connected; and   a plurality of wireless nodes each including a first receiver and a first transmitter,   each of the plurality of wireless nodes being connected to a corresponding plurality of submodules among the plurality of submodules constituting the arm by wired communication,   each of the plurality of wireless nodes transmitting a gate control signal based on a control protection command received via the first receiver to each of the corresponding plurality of submodules, and transmitting individual information received from the corresponding plurality of submodules via the first transmitter,   the plurality of wireless nodes being divided into a plurality of groups,   a plurality of channels of a first multiple access method each being allocated to a corresponding one of the plurality of groups, a plurality of subchannels of a second multiple access method each being allocated to a corresponding one of a plurality of wireless nodes included in each of the plurality of groups, the plurality of subchannels being divisions of a corresponding channel of the first multiple access method,   the first transmitter of each of the plurality of wireless nodes transmitting the individual information via an allocated channel and subchannel,   the power conversion device further comprising a control protection device,   the control protection device including:   a second transmitter to simultaneously transmit the control protection command that is common to the first receiver of each of the plurality of wireless nodes via a channel that is different from the plurality of channels of the first multiple access method, and   a plurality of second receivers each provided for a corresponding one of the plurality of groups, each second receiver receiving the individual information from the plurality of wireless nodes included in a corresponding group via a channel allocated to the corresponding group.   
     
     
         2 . The power conversion device according to  claim 1 , wherein the first multiple access method is frequency division multiple access, and the second multiple access method is time division multiple access. 
     
     
         3 . The power conversion device according to  claim 2 , wherein individual time slots are allocated to the plurality of wireless nodes included in each of the plurality of groups, and the first transmitter of each of the plurality of wireless nodes transmits the individual information in the allocated time slot. 
     
     
         4 . The power conversion device according to  claim 2 , wherein each of the plurality of wireless nodes conducts time synchronization based on a timing signal received from the control protection device. 
     
     
         5 . The power conversion device according to  claim 1 , wherein each of the plurality of wireless nodes generates the gate control signal according to a phase shift pulse width modulating method by comparing a voltage command value included in the control protection command with a carrier signal. 
     
     
         6 . The power conversion device according to  claim 5 , wherein, when there is a failed submodule among the corresponding plurality of submodules, each of the plurality of wireless nodes locally adjusts a phase shift amount so that a phase shift amount corresponding to the remaining plurality of submodules excluding the failed submodule from the corresponding plurality of submodules is even. 
     
     
         7 . The power conversion device according to  claim 1 , wherein
 a plurality of wireless nodes constituting each of the plurality of groups, and a plurality of submodules connected to these wireless nodes are accommodated in a plurality of insulating containers that are provided to respectively correspond to the plurality of wireless nodes and are stacked in a vertical direction, and   each of the plurality of insulating containers accommodates a corresponding wireless node, and a plurality of submodules connected to the corresponding wireless node.